Euclidean Geometry
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None
Drag any movable point (represented by a dot) to a different position or click on any point (dot or cross), line and/or circle to change it's color.
Point
Click anywhere on the applet to create a new movable point. You may also drag any preexisting movable point to a new position. If the mouse is over a point, the point will be highlighted.
Line
Click on any two distinct points, A and B. Draws the line through A and B. If you click on the screen, a new point will be created at that point, if none already exists there.
Line Segment
Click on any two distinct points, A and B. Draws the line segment with endpoints A and B. For the purposes of the following descriptions, a line segment is considered to be a line while a line is not a line segment.
Circle
Click on any two distinct points, A and B. Draws the circle centered at A that goes through B. If you click on the screen, a new point will be created at that point, if none already exists there.
Intersection
Click on any two lines and/or circles. If the two objects you selected intersect, the points of intersection will be drawn. In the case of the intersection of a line and a circle or the intersection of two circles, this may result in two points of intersection.
Angle Bisector
Click on any three distinct points, A, B and C. Draws the line which bisects the angle ABC. See Bisecting An Angle.
Centroid
Click on any three distinct points, A, B and C. Draws the centroid of the triangle with vertices A, B and C. See Centroid.
Circumcenter
Click on any three distinct points, A, B and C. Draws the circumcenter of the triangle with vertices A, B and C. See Circumcenter.
Circumscribed Circle
Click on any three distinct points, A, B and C. Draws the circle through through A, B and C.
Equilateral Triangle
Click on any two distinct points, A and B. Draws an equilateral triangle with side AB. The triangle is drawn so that vertex A immediately precedes B when reading the vertices in counterclockwise order. See Constructing An Equilateral Triangle.
Euler's Line
Click on any three distinct points, A, B and C. Draws Euler's line of the triangle with vertices A, B and C. See Euler's Line.
Incenter
Click on any three distinct points, A, B and C. Draws the incenter of the triangle with vertices A, B and C. See Incenter.
Inscribed Circle
Click on any three distinct points, A, B and C. Draws the circle of maximum area that fits inside the triangle with vertices A, B and C.
Inversion
Click on a point A and a circle C. Draws the inversion of point A across circle C. In other words, it draws the unique point B such that OAOB = R^{2} where O is the center of the circle and R is the radius of the circle. See Inversion of a point across a circle.
Midpoint
Click on any two distinct points, A and B. Draws the midpoint of A and B. See Constructing The Midpoint.
Orthocenter
Click on any three distinct points, A, B and C. Draws the orthocenter of the triangle with vertices A, B and C. See Orthocenter.
Parallel Line
Click on a point A and a line L. Draws the line through A and parallel to L. See Constructing A Parallel Line.
Perpendicular Bisector
Click on a line segment L, with endpoints A and B. Draws the line through the midpoint of A and B perpendicular to L. See Constructing The Perpendicular Bisector.
Perpendicular Line
Click on a point A and a line L. Draws the line through A and perpendicular to L. See Constructing A Perpendicular Line.
Point on Line
Click on a line L. Draws a movable point on L.
Point on Circle
Click on a circle C. Draws a movable point on C.
Projection
Click on a point A and a line L. Draws the point on L that is closest to A. In other words, it draws the intersection of L and the line through A perpendicular to L. See Projecting A Point Onto a Line.
Reflection
Click on a point A and a line L. Draws the reflection of point A across line L. In other words, it draws the point that is the mirror image of A on the opposite side of L. See Reflection of a point across a line.
Square
Click on any two distinct points, A and B. Draws a square with side AB. The square is drawn so that vertex A immediately precedes B when reading the vertices in counterclockwise order.
